Process of treating vegetable fibers.



' the treatment of flax straw fiber, althoughit' PROCESS OF TREATING: VEGETABLE FIBERS.

ascents.

Specification of Letters Patent. 2 Patented New, 2?), lltllllfi.

lfl'o brewing. Application filed September 17, 1918, Serial No. 790,205. Renewed April 24, 1918. Serial No.

ing Vegetable Fibers, of which the follow ing is a full, clear, concise, and exact description. I r My invention relates to improvements in processes of treating vegetable fibers to recover the pure'fiber-therefrom.

My invention is more particularly directed to 'a newand. additional step in the process of treating vegetable substances for the production of paper pulp or the like. Said new and additionalstep is preliminary to. andmay be merely a step which is-preparatory to the usual well known causticsoda, sulfite or sulfate processes Said preliminary treatment makes the material more amenable to the subsequent treatment, and the woody material isrendered more susceptible to ready and complete disintegration and is therefore more readily removed from the fiber. s

I shall describe my process as applied to is to be understood that it is by no means lim ted to its application to this material, but may be applied very' generally wherever itis desired to extract the cellulose from a vegetable fiber in order that the resulting product may be utilized either as a fiber adapted for use in the textile arts or to be used in the manufacture of paper, or in other arts.

I prepare the straw flax by breaking'it up between corrugated rolls, or by other suitable mechanism, into' lengths of about three quarters of an inch, the fiber,.of course, remaining full length. After brealn'ng up the straw in this manner, it is possible by agitating the material to sift out a great portion of the broken up woodga screen of about one inch mesh being used in this operation. About of the wood is removed by the screening process. During process practically all of the dust and dirt is also removed. After the straw is broken- 'up I moisten it with water. For this purpose I find it advisable to allow the straw to take up-not more than 70% of'its own weight of water. As the next-step in the of chlorin gas. F or this purpose said fiber is placed in gas chambers and chlorin gas admitted thereto, said fiber being subject to the action of the gas for about two hours,

during which treatment the fiber turns from a greenish brown to an orange yellow color. This treatment breaks down the glutinous material, the oil, the wax, etc, and renders the woody portion more susceptible to the boiling treatment which follows. For the boiling treatment either" the soda solution, the sulfite, or the sulfate solution may be used. I prefer to use a 10% soda solution. The

time occupied for the boiling process is about an hour. The receptacle used may be either rotary or the vomiting type of digester, or some other receptacle.

At the end of the boiling process, the material is light gray, almost white. Ilie wood is spongy and is almost completely disintegrated and may be readily washed out. The washing may be performed in the usual manner during which the product becomes still lighter in color. It is then bleached in the spent chlorin gas for about a minute, thereby completing the process.

x With reference to the preliminary chlorin treatment, I have found that without said treatment the wood material, after treatment in the usual manner, is hard and brittle. The action of the chlorin gas is such that the subsequent removal of said wood is not only greatly facilitated, but much more thorough and complete than in the prior processes.

WhatI'claim is: 0

1. In the manufacture of paper pulp or the like, the preliminary process of treating vegetable fibers, which consists in first breaking up the material to loosen the woody p01 jecting the same at ordinary temperature to the action of chlorin gas the screening 2. The process of treating vegetable fibers, which consists in first breaking up the material to loosen the woody portion from the fiber. proper, removing part of said woody portion, molstening the remaining product, subjecting the same at ordinary temperature to the action of chlorin gas in chambertand promptly boiling the product in a, suitable solution to disintegrate the remanning woody portion.

3. The process of treating vegetable fibers, which consists in first breaking up' the material to loosen the Woody portion from the fiber proper, removing part of said woody portion, moistening the remaining product, Sub ecting the same at ordinary temperature to the action of chlorin gas ina'chamber', then promptly boiling in a suit- 

